using System;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using NewLife.Collections;
using NewLife.Data;
using NewLife.Reflection;
using NewLife.Serialization;
namespace XCode.DataAccessLayer
{
partial class DAL
{
#region 属性
[ThreadStatic]
private static Int32 _QueryTimes;
/// <summary>查询次数</summary>
public static Int32 QueryTimes => _QueryTimes;
[ThreadStatic]
private static Int32 _ExecuteTimes;
/// <summary>执行次数</summary>
public static Int32 ExecuteTimes => _ExecuteTimes;
#endregion
#region 数据操作方法
/// <summary>根据条件把普通查询SQL格式化为分页SQL。</summary>
/// <param name="builder">查询生成器</param>
/// <param name="startRowIndex">开始行，0表示第一行</param>
/// <param name="maximumRows">最大返回行数，0表示所有行</param>
/// <returns>分页SQL</returns>
public SelectBuilder PageSplit(SelectBuilder builder, Int64 startRowIndex, Int64 maximumRows)
{
if (startRowIndex <= 0 && maximumRows <= 0) return builder;
// 2016年7月2日 HUIYUE 取消分页SQL缓存，此部分缓存提升性能不多，但有可能会造成分页数据不准确，感觉得不偿失
return Db.PageSplit(builder, startRowIndex, maximumRows);
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <returns></returns>
public DataSet Select(String sql)
{
return QueryByCache(sql, "", "", (s, k2, k3) => Session.Query(s), nameof(Select));
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="builder">SQL语句</param>
/// <param name="startRowIndex">开始行，0表示第一行</param>
/// <param name="maximumRows">最大返回行数，0表示所有行</param>
/// <returns></returns>
public DataSet Select(SelectBuilder builder, Int64 startRowIndex, Int64 maximumRows)
{
return QueryByCache(builder, startRowIndex, maximumRows, (sb, start, max) =>
{
sb = PageSplit(sb, start, max);
return Session.Query(sb.ToString(), CommandType.Text, sb.Parameters.ToArray());
}, nameof(Select));
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="builder">SQL语句</param>
/// <param name="startRowIndex">开始行，0表示第一行</param>
/// <param name="maximumRows">最大返回行数，0表示所有行</param>
/// <returns></returns>
public DbTable Query(SelectBuilder builder, Int64 startRowIndex, Int64 maximumRows)
{
return QueryByCache(builder, startRowIndex, maximumRows, (sb, start, max) =>
{
sb = PageSplit(sb, start, max);
return Session.Query(sb.ToString(), sb.Parameters.ToArray());
}, nameof(Query));
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public DbTable Query(String sql, IDictionary<String, Object> ps = null)
{
return QueryByCache(sql, ps, "", (s, p, k3) => Session.Query(s, Db.CreateParameters(p)), nameof(Query));
}
/// <summary>执行SQL查询，返回总记录数</summary>
/// <param name="sb">查询生成器</param>
/// <returns></returns>
public Int32 SelectCount(SelectBuilder sb)
{
return (Int32)QueryByCache(sb, "", "", (s, k2, k3) => Session.QueryCount(s), nameof(SelectCount));
}
/// <summary>执行SQL查询，返回总记录数</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public Int32 SelectCount(String sql, CommandType type, params IDataParameter[] ps)
{
return (Int32)QueryByCache(sql, type, ps, (s, t, p) => Session.QueryCount(s, t, p), nameof(SelectCount));
}
/// <summary>执行SQL语句，返回受影响的行数</summary>
/// <param name="sql">SQL语句</param>
/// <returns></returns>
public Int32 Execute(String sql)
{
return ExecuteByCache(sql, "", "", (s, t, p) => Session.Execute(s));
}
/// <summary>执行插入语句并返回新增行的自动编号</summary>
/// <param name="sql"></param>
/// <returns>新增行的自动编号</returns>
public Int64 InsertAndGetIdentity(String sql)
{
return ExecuteByCache(sql, "", "", (s, t, p) => Session.InsertAndGetIdentity(s));
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public DataSet Select(String sql, CommandType type, params IDataParameter[] ps)
{
return QueryByCache(sql, type, ps, (s, t, p) => Session.Query(s, t, p), nameof(Select));
}
/// <summary>执行SQL语句，返回受影响的行数</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public Int32 Execute(String sql, CommandType type, params IDataParameter[] ps)
{
return ExecuteByCache(sql, type, ps, (s, t, p) => Session.Execute(s, t, p));
}
/// <summary>执行插入语句并返回新增行的自动编号</summary>
/// <param name="sql"></param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns>新增行的自动编号</returns>
public Int64 InsertAndGetIdentity(String sql, CommandType type, params IDataParameter[] ps)
{
return ExecuteByCache(sql, type, ps, (s, t, p) => Session.InsertAndGetIdentity(s, t, p));
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public DataSet Select(String sql, CommandType type, IDictionary<String, Object> ps)
{
return QueryByCache(sql, type, ps, (s, t, p) => Session.Query(s, t, Db.CreateParameters(p)), nameof(Select));
}
/// <summary>执行SQL语句，返回受影响的行数</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public Int32 Execute(String sql, CommandType type, IDictionary<String, Object> ps)
{
return ExecuteByCache(sql, type, ps, (s, t, p) => Session.Execute(s, t, Db.CreateParameters(p)));
}
/// <summary>执行SQL语句，返回结果中的第一行第一列</summary>
/// <typeparam name="T">返回类型</typeparam>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型，默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public T ExecuteScalar<T>(String sql, CommandType type, IDictionary<String, Object> ps)
{
return ExecuteByCache(sql, type, ps, (s, t, p) => Session.ExecuteScalar<T>(s, t, Db.CreateParameters(p)));
}
#endregion
#region 事务
/// <summary>开始事务</summary>
/// <remarks>
/// Read Uncommitted: 允许读取脏数据，一个事务能看到另一个事务还没有提交的数据。（不会阻止其它操作）
/// Read Committed: 确保事务读取的数据都必须是已经提交的数据。它限制了读取中间的，没有提交的，脏的数据。
/// 但是它不能确保当事务重新去读取的时候，读的数据跟上次读的数据是一样的，也就是说当事务第一次读取完数据后，
/// 该数据是可能被其他事务修改的，当它再去读取的时候，数据可能是不一样的。（数据隐藏，不阻止）
/// Repeatable Read: 是一个更高级别的隔离级别，如果事务再去读取同样的数据，先前的数据是没有被修改过的。（阻止其它修改）
/// Serializable: 它做出了最有力的保证，除了每次读取的数据是一样的，它还确保每次读取没有新的数据。（阻止其它添删改）
/// </remarks>
/// <param name="level">事务隔离等级</param>
/// <returns>剩下的事务计数</returns>
public Int32 BeginTransaction(IsolationLevel level = IsolationLevel.ReadCommitted)
{
CheckDatabase();
return Session.BeginTransaction(level);
}
/// <summary>提交事务</summary>
/// <returns>剩下的事务计数</returns>
public Int32 Commit() => Session.Commit();
/// <summary>回滚事务，忽略异常</summary>
/// <returns>剩下的事务计数</returns>
public Int32 Rollback() => Session.Rollback();
#endregion
#region 缓存
/// <summary>缓存存储</summary>
public DictionaryCache<String, Object> Store { get; set; }
/// <summary>数据层缓存。默认10秒</summary>
public Int32 Expire { get; set; }
private DictionaryCache<String, Object> GetCache()
{
var st = Store;
if (st != null) return st;
var exp = Expire;
if (exp == 0) exp = Db.DataCache;
if (exp == 0) exp = Setting.Current.DataCacheExpire;
if (exp <= 0) return null;
Expire = exp;
lock (this)
{
if (Store == null)
{
var p = exp / 2;
if (p < 30) p = 30;
st = Store = new DictionaryCache<String, Object> { Period = p, Expire = exp };
}
}
return st;
}
private TResult QueryByCache<T1, T2, T3, TResult>(T1 k1, T2 k2, T3 k3, Func<T1, T2, T3, TResult> callback, String prefix = null)
{
CheckDatabase();
// 读缓存
var cache = GetCache();
if (cache != null)
{
var sb = Pool.StringBuilder.Get();
if (!prefix.IsNullOrEmpty())
{
sb.Append(prefix);
sb.Append("#");
}
Append(sb, k1);
Append(sb, k2);
Append(sb, k3);
var key = sb.Put(true);
return cache.GetItem(key, k =>
{
Interlocked.Increment(ref _QueryTimes);
return callback(k1, k2, k3);
}).ChangeType<TResult>();
}
Interlocked.Increment(ref _QueryTimes);
return callback(k1, k2, k3);
}
private TResult ExecuteByCache<T1, T2, T3, TResult>(T1 k1, T2 k2, T3 k3, Func<T1, T2, T3, TResult> callback)
{
if (Db.Readonly) throw new InvalidOperationException($"数据连接[{ConnName}]只读，禁止执行{k1}");
CheckDatabase();
var rs = callback(k1, k2, k3);
var st = GetCache();
st?.Clear();
Interlocked.Increment(ref _ExecuteTimes);
return rs;
}
private static void Append(StringBuilder sb, Object value)
{
if (value == null) return;
if (value is SelectBuilder builder)
{
sb.Append(builder);
foreach (var item in builder.Parameters)
{
sb.Append("#");
sb.Append(item.ParameterName);
sb.Append("#");
sb.Append(item.Value);
}
}
else if (value is IDataParameter[] ps)
{
foreach (var item in ps)
{
sb.Append("#");
sb.Append(item.ParameterName);
sb.Append("#");
sb.Append(item.Value);
}
}
else if (value is IDictionary<String, Object> dic)
{
foreach (var item in dic)
{
sb.Append("#");
sb.Append(item.Key);
sb.Append("#");
sb.Append(item.Value);
}
}
else
{
sb.Append("#");
sb.Append(value);
}
}
#endregion
}
}
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